Add generate! and validate! modes
add WebMockHelper for WebMock->Pacto integration
add new relish tests
Merge branch 'modes' into v0.3.0.rc
why would a contract lack a request?
store RequestPattern instead of RequestStub
separate building stub from request pattern
only stub if stubbing, but always return a RequestPattern
Merge branch 'validate_without_stubbing' into v0.3.0.rc